Field
The present invention relates to a persimmon leaf-derived polysaccharide fraction and a preparation method thereof and more particularly, to a persimmon leaf-derived polysaccharide fraction comprising 70-90 wt % (based on the total weight of the polysaccharide fraction) of neutral sugar and 10-30 wt % (based on the total weight of the polysaccharide fraction) of uronic acid, a preparation method and a use thereof.
Discussion of the Background
Persimmon leaves have a vitamin C content that is 20 times higher than that of a lemon, and thus, are used as health tea. Persimmon leaves have the benefits of facilitating blood circulation, strengthening blood vessels, and being effective against scurvy, anemia, heart diseases, arteriosclerosis and cerebral hemorrhage. However, there have been little or no studies on the effects of persimmon leaves on the immune system.
The complement system is the primary immune system and is known to be activated by the following three pathways: a classical pathway which is activated by the binding of antigen-antibody complexes to C1q; an alternative pathway in which factor B and factor D are involved with C3b existing in blood and which is non-specifically triggered by activators such as lipopolysaccharide and endotoxin; and a lectin pathway which is activated by lectin that binds specifically to mannose in the cell wall.
Natural materials known to be involved in the activation of the complement system include lentinan isolated from Lentinus edode, polysaccharide K (PSK) isolated from Coliolus versicolar, etc.
Korean Patent Application Laid-Open Publication No. 10-2003-0024111 discloses a composition for lowering blood lipid levels, which comprises a persimmon leaf extract and is used to lower blood lipid levels and protect liver functions. In addition, a paper on the antioxidant and anti-allergic effects of a persimmon leaf extract (Journal of Food Science and Nutrition, 2009, Vol. 38, No. 12, 1691-1698) was published. However, neither the immune-enhancing effect of a persimmon leaf, nor a polysaccharide having a sugar composition disclosed by the present inventors, has been known so far.